With regard to such an electronic control unit as described above, the electronic control units disclosed in PLT-1 and PLT-2, described later, are known. In the technology disclosed in PLT-1, an upper-side heat sink and a lower-side heat sink, which each function also as the electrodes of a semiconductor chip, are soldered to the top surface and the bottom surface, respectively, of the semiconductor chip, and the upper-side and lower-side heat sinks are cooled by coolant.
In the technology disclosed in PLT-2, a protruding portion of a heat sink abuts against the top surface of a semiconductor chip, through the intermediary of an intermediate member having an insulating performance and a conductivity, and a protruding portion of the heat sink abuts against the top surface of a copper thin-film connection wire, through the intermediary of an intermediate member having an insulating property and a heat-conductive property.